Control means for fluid-operated cylinders



Mar. 13, 1923. A M '60W 11,448,531..

CONTROL MEANS FOR FLUID OPERATED CYLINDERS.

FILED APR4.191s. 2 SHEETS-SHEET 1.

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A. M. GOW.

CONTROL MEANS FoR FLUID OPERATED CYLINDEHS.

2 SHEET HSHEET 2.

FILED APRa 4,1918.

eezandaerMGoM/ Patented Mar. 13, 1923.

UNHTD STT maaar aaraar castes.

ALEXANDER M. GOW, OF DULUTH, MINNESOTA; AMERICAN EXCHANGE NATIONAL BANK OF DULUTH EXECUTOR OF THE ESTATE OF SAID ALEXANDER M. GOW, DE-

CEASED.

CONTROL MEANS FOR FLUID-OPERATED CYLINDEBS.

Application led April 4, 1918.

T 0 all lwhom it may concern Be it known that I, ALEXANDER M. Gow, a citizen of the United States, and resident of Duluth` in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Control Means for Fluid-Operated Cylinders, of which the following is a specification.

This invention relates to fluid operated cylinders, and more particularly to valve mechanism therefor.

In the operation of fluid operated dump cars it is desirable that the air be cut off from the operating cylinder as soon as the piston has reached the end of its operating stroke. In a train comprising several cars, owing to the difference in the way the cars are loaded, one car may dump at twenty pounds pressure, while another car may require one hundred pounds. Air being admitted to the dump line, it is obvious that the car which will dump under the influence of twenty pounds pressure will go over first, and that unless the air is immediately cut ofi' from the corresponding cylinder, one hundred pounds pressure will accumulate in said cylinder performing no service and at the same time constituting a serious waste of air. To obviate this waste, it is the practice to attach to the mechanism an operating rod which closes a cut-out cock and release valve on the line to the cylinder. The objection to this construction is that the moving parts are subject to derangement and breakage and constant repairs and adjustment are necessary.

Therefore, one of the objects of my present invention is to obviate the use ofpcut out valve operating mechanism which is subject to derangement and faulty operation.

Another object is to improve the control mechanism for fluid operated cylinders wherebyy efiicient and safe operation of the ears may be obtained.

These and other objects are accomplished by providing valve mechanism disclosed in the drawings, in which- Figure 1 is a diagrammatic view of an air dumping system embodying my invention; and.

Figure 2 is a diagram of a modification thereof.

Figure 3 is a view similar to Figure 1,

Serial No. 226,601.

the several parts being in positions to supply .fluid pressure to the cylinder.

4`igure 4 is a view similar' to Figure 2.

Figure 5 is a sectional view, similar to Flgure 4, and showing the valve in its open position.

Figure 6 is a detail sectional view of one of the valve members of the invention.

Referring first to Figures 1 and 3 of the drawings, it will be noted that I have shown an air cylinder 1() in which a piston 11 is operable. To illustrate one use of my arrangement, one end of the stem of the piston may be operatively connected to means for dumping or righting the body of the dump car, not shown. This piston is adapted to be moved upward lwhen air or any other suitable fluid is admitted thereunder through a pipe 12, which extends between the cylinder 10 and a chamber 13 in valve casing 14. Extending 'between another air chamber 15 and a three-way valve 16 is a pipe 17. Connected to this pipe 17 is an air connection 18 extending into an orifice 19 near the top or one end of the cylinder 10. Within this air connection 18 is a check valve 20 and another valve 21 preferably hand-operated, to be referred to later. lntermediate the valves 20 and 21 is an air pipe or connection 22 extending between the alr connection 18 and the upper end of the casing 14. Movably mounted in the casing 14 is a cut-ofi" valve 23 having a dierential piston with a lower portion 24 smaller than its upper portion 25. Connected to the smaller portion 24 of the valve is a valve member 26 which cooperates with a valve seat 27 formed in a partition 28 separating the valve chambers 13 and 15. In the position of the parts shown in Figure 1, the three-way valve 16 is closed and there is no airunder pressure between the valve 16 and any part of the mechanism.

ln connection with the operation of this mechanism, when the three-way valve 16 is opened, as in Fig. 3, air is admitted from any suitable source of supply 29 through pipe 17, causing check Valve 20 to close immediately. Compressed air is admitted under piston 24 of valve 23, forcing the latter upwardly and thus opening the passage between pipe 17 and pipe 12 and admitting air to the cylinder 10 under piston 11. This .upwardly under different conditions.

causes the piston 11 to move upwardly for dumping or righting the body ot the. dump car` or for any other suitable use. lVhen the piston 1l passes the aperture or orilice 1S) near the,upper'end ol' the cylinder, air is admitted l'rom the cylinder 1() and back through the valve 2l and pipe 22 to the upper part of the valve easing 14. on top ol' the piston 25 ot valve 2?, and in view ol the tact that the area otthis piston 25 is greater than' the bottom area ol piston 24, the valve 23 is caused to move into a closed position. as shown in Figure 1, thereby cutting oil communication between the pipes 17 and 12 and cutting oli' the supply ot' compressed air to the cylinder 10. lfVhen it is desired to release the air in the cylinder 1() to permit the piston 11 to return to its lower position, the three-way valve is thrown to the position shown in Fig. 1. This releases the air in pipe 17 and from under the check valve 20, which immediately drops open, thereby releasing pressure on top ot the valve piston 25 and the main piston 11 starts to descend. The pressure fluid below the piston 11 is transmitted through pipe l2 to the under side 26 or smallest pressure surface ot the valve 14,

' thereby raising the same and leaving a free opening for the discharge ot air from the cylinder 10 through the three-way valve 1G. It will be noted that the cut out valve 23 has three different pressure surfaces, one for receiving pressure to move the valve downwardly and two for moving the vallye ie function of the valve 21 is to render inoperative the valve 23 in case ot its derangement. If the valve 21 is closed, then the cut-off and release valve mechanism serves no purpose, but does not prevent the actuation of the piston by means ot the three-way valve 16. The valve 21` is provided with a vent 30 through which the pressure acting on the top of the piston 25 is relieved when the valve 21 is closed to the cylinder 10. When the valve 21 is open to establish communication between both pipes 18 and 22 and the cylinder 10 the vent 30 is closed. Under normal conditions the valve 21 is open and its vent closed. Should the piston 11 descend in the cylinder 10 to a point to uncover the opening 19 the pressure above the` piston 25 being reduced admits of the valve 23 opening. As a result the pressure in the pipe 17 passes into pipe 12 and cylinder 10 and returns the piston 11 to the desired elevated position. It will thus be understood that the valve 23 is automatic in action and maintains a predetermined pressure in the lower portion of the cylinder 10 to keep the piston 11 elevated therein under certain conditions.

In Figures 2, 4 and 5 I have shown a modification, wherein l dispense with thel pipe lh' aud its valve. 2t), and inthe place thereof l employ a check valve 20 located within a chamber formed in the intermediate. portion ot the cut oil' valve 2li. 'lhis valve is in the form ot' a disc somewhat smaller vin diameter than the internal diameter ot' the said chamber, and provided with an upwardly bevelled or tapered periphery designed to seat upwardly against the. correspondiugly tapered or bevelled valve seat 20l provided at the top of the chamber. ()n the under side ot' the check valve. 20 there are provided radially disposed guide wings 20 the outer edges otl which have a working tit within the chamber so as to guide the. valve and prevent lateral looseness thereof. '.lhe diameter of the valve disc is of course greater than the diameter otl the opening through the valve seat, but is less than the diameter of the containing chamber so as to permit the passage ot' air under pressure around the periphery of the check valve under certain conditions. lith the parts in the position shown in Figure 2 of the drawings, and the three-way valve 16 is opened, fluid pressure is admitted through the pipel 17 into tho chamber 15 and against the bottom portion 2-1 of the cut-off valve 28, whereupon the latter valve will rise to the position shown in Figure 5 of the drawings, thereby establishing communication -between the pipes 17 and 12 so as to'supply fluid pressure to the cylinder 10 beneath the piston 11. At the sameI time air passing from the chamber 15 through the ports 31 will act upon the lower side ot the check valve 25 and seat the. latter upwardly so as to prevent the passage of fluid pressure upwardly through the pipe 22. When' the piston. 11 has passed the orifice 19` as shown in Figure -1 of the drawings, fluid pressure will pass from the under side of the piston 11 back through the valve 21 and pipe 22 into the top of the valve casing 14 where it will act upon the large areaI of the piston portion 25 of the cut-ofil valve and seat the latter downwardly, thereby cutting ofi' further supply of fluid pressure to the cylinder 10. In this position of the parts, the check valve 20' will remain seated because its lower side is subject to fluid pressure passing from the chamber 15 through the ports 31 and into the chamber containing the check valve, the lower area of the check valve, subject to upward pressure, being greater than the upper surface of the check valve 20 which is subject to downward pressure through the opening in the valve seat 20a. Should the piston 11 descend below the orifice 19, due to leakage or otherwise, there will be an unbalanced condition ot' pressure at opposite sides of the cut-oli' valve 23, wherefore,

15 will cause the valve 23 to rise and admit pressure fluid into, the cylinder l10 until the piston 11 rises above the Yorifice 1%?, whereupon the valve parts will resume thelr positions and cut ofl further supply of' fiuid to the under side of piston 11, wherefore it will be understood that the piston will be automatically maintained in its elevated position. i

With' the parts in the positions shown in Figure 4, and to permit the piston 11 to return to its original position at the opposite end of the cylinder 10, the valve 16 is operated to shut of pressure from the pipe Q9 and to open the vent to the atmosphere, whereupon pressure will be relieved upon the under side of the check valve 20 and said valve will drop to its lowermost position, thus permitting fluid pressure to flow from the cylinder 1() through the pipe 22 around the valve 20', through the ports 31 and thence through the pipe 17 to the atmosphere, the result of which is to relieve pressure on the under side of the piston 11 and the latter will descend. As soon as the piston 11 descends below the port 19, the pressure on the under side of the valve 23 will cause the latter to rise to the position shown in Figure 5, whereupon the pressure fluid will have an unobstructed passage through the pipe '12, the chamber 13, the port 27, the chamber 15 and the pipe 17 to the atmosphere, and the plsto-n 11 will thus be permitted to promptly return to its orig-` inal position.

By means of the arrangements shown in the drawings, it will be noted that the automatic differential valve is adapted to be -closed when air under pressure near the top of the cylinder is admitted to the top of the valve, and the check valve 2O 20 will release air under pressure from the top of' the valve 23 when the air, which is enclosed in the pipe between the operating valve 16 and the check Valve 2O or 20', is released.

By means of this arrangement a simple and effective control mechanism for fluid operated dump cars is provided, obviating the use of parts which are easily deranged or otherwise rendered inoperative.

It is intended to cover other modifications of the invention falling within the spirit and scope of the following claims.

I claim:

1. In control mechanism for a fluid operated cylinder, the combination of a cylinder. a piston operable therein, and means whereby the supply of air to Said cylinder is cut off and air pressure trapped within the cylinder by pressure within the cylinder when the piston therein has reached a predetermined position to hold the piston in said predetermined position.

2. In control mechanism for a fluid operated cylinder, the combination of a cylinder,

a piston operable therein, and valve means whereby the supply of airto said cylinder is cut ofi' and air pressure trapped Within the cylinder by pressure within lthe cylinder when the-piston therein has reached a predetermined position to hold the piston in said ,redetermined.posion trap-ping pressure in the cylinder b-y means.

of cylinder pressure when the piston therein has reached a predetermined position with respect to one of the valve connections with the cylinder to hold the piston in said predetermined position. i'

5. In control mechanism for a fluid operated cylinder, the combination of av cylinder,

a-piston operabletherein, and adifl'erential valve operatively connected to different parts of said cylinder fo-rautomatically cutting off' the supply of pressure'fluid and n control mechanlsm for a fluid operated cylinder, the lcombination of a cylinder,

trapping pressure in the cylinder by presi sure within thel cylinder when the piston therein has reached a predetermined position to hold the p-iston in said predetermined position.

6. In control mechanism for a -fluid operated cylinder, the combination of a cylinder, a piston operable therein, means for manually cutting ofi' the supply of fluid pressure and for venting the mechanism, and a. cut-out valve operatively connected to said cylinder operable by pressure within said cylinder to automatically effect opening of the cut-out valve when the pressure fluid supply is manually cut off and the mechanism Vented.

7. In control mechanism for a fluid operated cylinder, the combination of a cylinder, a piston operable therein. means for manually cutting off the supply of' fluid pressure and for venting the mechanism, a cut-out valve operatively connected to said cylinder operable by pressure within said cylinder, and a check valve operatively associated with said cut-out valve to automatically effect opening of the cut-out valve `when the pressure fluid supply is manually cut ofi' and the mechanism vented.

8. In control mechanism Jfor a fluid operated cylinder, the combination of a cylinder,

a piston operable therein, and valve means operatively connected with different portions a piston operable the-rein, means for manually cutting off' the supply of pressure fluid and for yventing the mechanism, a cut-out valve operatively connected to said cylinder for cutting off' the supply of pressure fluid to the cylinder at a predetermined position of the piston, and a check valve Within said cut-out valve, said check valve being operable by pressure of' the fluid Within the cylinder to automatically lefl'ect opening of the cut-out valve when the air supply is manually cut off and the mechanism is vented.

10. Incontrol mechanism for a fluid operated cylinder, the combination of a cylinder, aI piston operable therein, means. for

l manually cutting ofll the supply of' p-ressure fluid and for venting the mechanism, a cut-out valve operatively associated with said cylinder for automatically cutting off the supply vof pressure fluid and trapping pressure in the cylinder by means of cylinder pressure', and a check valve mounted in said cut-out valve to automatically effect opening of the cut-out valve When the supply of pressure fluid is manually cut off and the mechanism vented.

11. In control mechanism for a fluid operated cylinder, the combination of a cylinder, a piston operable therein', means for` manually cutting off the supply of pressure fluid and for Venting the mechanisma cutout valve for automatically cutting ofl' the supply of' pressure fluid and trapping pressure fluid in the cylinder by means of cylinder pressure, and a check valve, one of said valves being mounted in operative association with the other to automatically effect opening ofthe other valve when the supply of pressure fluid is manually cut off and the mechanism vented.

12. In control mechanism for a fluid operated cylinder, the combination of a cylinder, a piston operable therein, means for manually cutting` ofl1 the supply of pressure fluid and for venting'the mechanism, a cutout valve for automatically cutting offl the supply of pressure fluid and trapping pressure fluid in the cylinder by means of cylinder pressure, and a check valve, one of said valves beingl mounted Within the other to automatically effect opening of the other valve when the supply of pressure fluid is manually' cut off and the mechanism vented.

Signed at Duluth, Minnesota, this 1st day of April, 1918.

ALEXANDER M. Gow.' 

